Question | Answer |
what is osmosis? | diffusion of water across a partially permeable membrane from an area of high water concentration to an area of low water concentration |
why can't sugar be transported by osmosis? | the membrane is partially permeable, meaning no large molecules can fit through |
what conditions will have to apply for water to diffuse into the plant? | high concentration of water outside of the cell
low concentration of water inside the cell |
what coniditions will have to apply for water to diffuse out of the plant? | low concentration of water outside of the cell
high concentration of water inside the cell |
what does flaccid mean? | soft and floppy |
when does a cell become flaccid? | when there's a higher concentrations of water inside the cell |
what happens when water enters a plant? | cell swells upt
increase in water pressure against the cell wall |
what is turgor pressure? | water pressure against the cell wall |
what does turgor pressure cause? | the cell to become turgid |
what does turgid mean? | hard and rigid |
what happens when water leaves a plant? | cell contents shrink
less water pressure against the cell wall |
what does less water pressure against the cell wall cause? | cell contents are plasmolysed
cell collapses |
how do plants reduce their water loss? | having few stomata
plants can open and close their stomata |
which cell controls whether the stomata opens or closes? | guard cells |
how does a stomata open? | 1.water enters from other cells
2. chloroplasts make sugar
3. guard cells become turgid
4. stoma opens |
what happens when a blood cell of an animal gains lots of water? | bursts (lysis) |
what happens when a blood cell of an animal loses lots of water? | shrinks (crenate) |
why does a blood cell of an animal either burst or shrink? | it has no cell wall for support |
how are root hairs adapted to absorb lots of water from the soil? | long and thin
large surface area |
what is the evaporation of water from leaves called? | transpiration |
why is transpiration useful? | -cools the plant
-brings water to the leaves for photosynthesis
-cell full of water gives support
-water moving up the stem carries useful dissolved minerals |
how does the leaf prevent too much water from evaporating? | -has a waxy covering called the cuticle
- stomata mainly on its shaded underside |
what helps to support a plant? | inelastic cell walls |